Fuel-injection device for diesel motors without compressors



E. FREY FUEL INJECTION DEVICE FOR DIESEL MOTORS WITHOUT CQMPRESSORS July 29 1924.

Filed March '7. 1924 2 Sheets-Shea; 1

uly 29, 1924 1,502,945

E. FREY v FUEL INJECTION DEVICE FOR DIESEL MOTORS WITHOUT COMPRESSORS Filed March 1924. 2 Sheets-Sheet 2 Patented July 29, 1924.

. umr azo STATES 1,502,946 PATENT OFFICE.

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Application filed March 7, 1924. Serial No. 697,653.

torsWithout Compressors, of which thefollowing is a specification.

My invention relates to a fuel-injection device for'use in connection with Diesel-motors; more especially it relates to a regulable injection pump for use in connection with Diesel-motors without a compressor, this pump being driven by a cam, aswell as by a spring, as is fully described hereinafter. The suction-valve of the. pump operates in known manner as return-flow valve. The stroke ofthe plunger of the pump can be varied insuch a manner by means of a shiftable intermediate lever arranged between the driving cam and the plunger that, on one side, the plunger can enter more or less deeply into the pump chamber, although the total stroke remains approximately equal, and that, in spite thereof, on the other hand, the plunger reaches through a certain height always at the same point in the en ine cycle.

The feed-pump is distinguishd From'similar ones by the feature that the same motion is transmitted to the suction valve, which can be adjusted in such a manner that during the suction stroke it. touches the seat provided for it always at that position of the plunger which this latter passes in the same point of time at all loads.

My invention is illustrated by way of example in the accompanying drawing in which Figure 1 is a longitudinal section through an arrangement and;.combination of parts according to my invention, and Figure 2 is a modification thereof.

Referring to Figure 1, the shaft 2' is supported in the casing 1 and carries the plunger-actuating cam 3 which acts on the guidemember 1 of the plunger 5. The guidemember 1 is subjected to the pressure of a spring 6 housed therein, and the plunger performs its suction stroke under the pressure of this spring. Between the cam 3 and the guide-member 4 is inserted a" regulating intermediate arm or lever 8 which is hinged at 9 to a slidea i that can be shifted inwards 1; outwards by,means of an arm or lever 25 assured us a shaft as. U I w he suction-valve 10 is subjected to the pressure of a spring 11 which-always tends to close it; it is opened during the suction period firstly by means of a lever or arm 17 supported at 18 in the casing 1 of the device and engaging with its free end a recess 4* in the guide-member 4; secondly by a lever or arm 14 supported at 15 on the top of the casing and provided with an adjustable transmlssion screw 13 which depresses the valve stem 10' and opens, ,thus, the valve 10; and thirdly by a rod 16 connecting the lever or arm 17 with the lever or arm 14, as shown.

The liquid fuel enters into the pump casing through the aperture 12 and fiows-be tween the opened valve 10 and its seat down into the pump chamber 1.

a When the valve 10 has been closed by the spring 11 owing to the arm or lever 14 having been lifted by the guide member. 4 which has been lifted, in its turn, by the cam 23, the liquid fuel is forced out of the pump chamber 1 by the plunger 5 which is moved" upwards together with said guide-member 4. The fuel leaves the chamber 1 through a channel 19 and enters into an annular or cylindrical chamber 20 enclosing a valve 20 which serves as both the pressure valve and the injection valve of the pump. This valve is kept closed by a spring 21 enclosed in the body thereof, as shown, and this latter is pressed inwards and the spring is correspondingly compressed by the pressure of the fuel on'the annular surface between the larger and the smaller diameter of said valve. The fuel then escapes at 23 into the cylinder. The upper arm 1 which forms a lateral extension of the standard or column 1 of the casing 1 is connected with a suitably located flange of the cylinder bymeans of the flange 23 and a plurality of bolts (not shown).

The stroke of the valve 20 is generally only very short and is limited by an abutment member 22 which is inserted into the inner end of the bore containing said valve.

The spring 21 is enclosed in cavities of the The manner of operation of the pump is as follows:

The position of the slide 24 as shown is that for full load, and the'upper movable I parts of the device are in the position in arm 8 and the plunger will be moved upwards for a way corresponding to the distance 'f, and a corresponding amount of fuel will now be injected into the cylinder. The distance "f indicates, and corres nds to, the longest effective delivery stro e of the pump. While the injection is taking place, the regulating screw 13 is being lifted off the valve stem by the lever or arm 14, that is to say, by the guide-member 4,

-the lever or arm 17, the rod 16, and said lever or arm 14, and when the deliver stroke has been finished, the suction stro e commences immediately thereafter, the plunger 5 moving now downwards for a length of way correspondin to the sum of the distances 7 plus 7*. l ile the distance or way f is being covered, the suction valve remains closed under the comparatively strong pressure of the spring 14, but while the distance or way 1' is being covered, the suction valve is opened by the finally greater pressure of the spring 6, this pressure being transmitted to the valve 10 by the parts 4, 17, 16, 14, 13, and 10'. The pump-chamber 1' is now again filled up with the liquid fuel, and this phase being finished, when the plunger 5 has made its entire suction stroke.

f plus 1', the plunger moves now again upwards and forces another amount of the liquid into the cylinder, as already described, but while the path 1' is being covered the suction valve remains open so that a corresponding amount of the fuel-is forced back around said valve. Then this latter is closed (position shown in Figure 1) and only now the actual injection takes place.

If, in order to reduce the amount of fuel to be injected, the slide 24 and the arm 8 are shifted to the right, the operating end of r the arm 8-rema1ns always in contact with the guide-member 4 and with the cam owing to the appropriate shape of the profile of {algae latter, without any shifting of the mem-' The effective delivery stroke is reduced and, thus, the injection time is diminished corresponding to the shifting of'the parts 24 and 8 to theright, whereas the time of commencement of the injection remains the same it was. If the parts 24 and 8 are .shifted to the right for a length of way corneoaeae ing the whole delivery stroke and is closed only in the upper dead centre of the plunger.

The above-mentioned little diagrammatical representation at the left of the lower part of Figure 1 shows the dependency f the effective pressure-stroke portion f, as well as of the return-flow strokeportion 1', upon the shifting of the parts 24 and 8.

In lieu of a rocker arm such as 8-which, for the sake of simplicity, has been illustrated without a pistona bell-crank lever might be used, and the position of the fulcrum thereof could be altered, for instance by means of an eccentric, in such a manner that, on one side, said lever could slide on the suitably shaped cam without, on the,

other side, shifting the plunger.

. While in the example-illustrated in Figure 1 the fuel-valve 10 is operated by the intermediary of levers and rods, as shown and described, another example is shown in Figure 2 where said valve is controlled by the plunger 5; it is-devised to form a 50-- called drag-valve, being provided with a downwardly extending U-shaped member 10 which is coupled with the plunger 5 by an extension 5 thereof and a head 5 of this extension. The upper end of the spring 11 bears against said member 10. The valve is, thus, 0 ened by the parts 5 5 5" and closed by the spring 11. The position of the arrangement and combination of parts shown in Figure 2 (excepting the shaft and the cam) is the standstill position; the position of the shaft and the cam is the same as in Figure 1.

Concerning the manner of operation there is no material difference with respect to Figure 1, except the feature that owing to the direct control by means of the plunger the return-flow stroke-portion 1' is transmitted to the suction-valve 10 without any diminution.

In order to provide for the possibility to adjust the point of the time of ignition, the plunger 5 is, in Figure 2, not made integral with the guide-member 4, as in Fi ure 1, but forms a separate part which is screwed into the member 4. By turningthe plunger in one or the other direction the moment of closing of the valve 10 can be so adjusted that the fuel-injection commences just in the point of time intended.

I claim:

1. A fuel injecting device of the character described, comprising a casing, a plunger and a guide member therefor, a cam mounted beneath said guide member, a slide mounted for movement at right angles to said plunger, a regulating arm hinged at one end to said slide with its free end interposed between said guide member and cam, a swingingly-mounted arm loosely engaged in said slide, a suction valve movable in line with the 'plunger, and means operably connected with said guide and valve for actuating the latter.

2. A. fuel injecting device of the character described, comprising a casing, a plunger and a guide member therefor, a cam mounted beneath said guide member, a slide mounted for movement ,at right angles to said plunger, a regulating arm hinged at one end to said s'lide with its free end interposed between said guide member and cam, a swingingly-mounted arm loosely engaged in said slide, a suction valve movable inline with the plunger, and means operably connected with said guide and valve for actuating the latter, there being a chamber between the plunger and valve seat with a channel leading from the upper end of said chamber.

3. A fuel injecting device of the characterdescribed, comprising acasing, a plunger and a guide member therefor, a cam mounted beneath said guide member, a slide mounted for movement at right angles to said plunger, a regulatin arm hinged at one end to said slide with its free end interposed between said guide member and cam, a swingingly-mounted arm loosely engaged in said slide, a suction valve movable in line with the plun er, means operably connected with said gui e and valve for actuating the latterfthere being a chamber between the plunger and valve seat with a channel leadmg from the upper end of said chamber, and a valve controlling the flow of fuel from said channel.

4. A fuel injecting device of the character described, comprising a casing, a plunger and a guide member therefor, a cam mounted beneath said guide member, a slide mounted for movement at right angles to said plunger, a regulating arm hinged at one end to said slide with its free end interposed between said guide member and cam, a swingingly-mounted arm loosely engaged in said slide, a suction valve movable in line with the plunger, and spring means for closing said valve during the early upward movement of the plunger;

In testimony whereof I hereunto afiix my signature.

ERNST FREY. 

